An exhausted Nicolas Massu beat Mardy Fish in five tortuous sets on Sunday to win Chile their second gold medal at an Olympic Games less than 24 hours after helping them to their first.

The 24-year-old, who had not won a single match on a hard court this year coming into the Games, beat the American 6-3, 3-6, 2-6, 6-3, 6-4 to land the men's singles title in the tennis event.

A medal ceremony, news conference and mandatory dope test had meant Massu had not left the tennis stadium until after 0400 on Sunday morning after his marathon gold medal-winning performance in the men's doubles with Fernando Gonzalez which had started on Saturday night.

On Sunday, he looked simply shattered and, after a strong start, seemed to fade in the warm Greek night as his legs started to cramp.

But the player known to his fans as "the vampire" clearly enjoys his late-night encounters and, thanks to vociferous support and single-minded determination, he closed out a famous victory in exactly four hours.

Earlier in the day, Li Ting and Sun Tian Tian won China's first Olympic medal in tennis, taking the women's doubles gold with a solid victory over Spain.

The Chinese rolled over second seeds Conchita Martinez and Virginia Ruano Pascual 6-3, 6-3 on centre court before running round the arena draped in the Chinese flag.

Their victory, achieved in 89 minutes, was greeted by exuberant celebrations from the many Chinese fans in the tennis centre.